A cold storage heat exchanger typically includes: a plurality of flat refrigerant pipes arranged in parallel to one another at regular intervals with their flat portions facing one another, fins, each of which is disposed in a gap between flat portions of adjacent ones of the refrigerant pipes and contacts air passing through the gap; and a cold storage medium container inserted in rows of the refrigerant pipes and the fins and containing a cold storage medium.
The cold storage heat exchanger is generally used as an evaporator in a refrigeration cycle of a vehicle air conditioner or other apparatus. Thus, a refrigerant supplied through a condenser and an expansion valve by a compressor driven by an engine flows in the refrigerant pipes and evaporates in the pipes. This refrigerant takes heat of vaporization from air flowing in the gap between the flat portions of adjacent refrigerant pipes, and cools air for cooling operation. At this time, cooling capacity is stored by the cold storage medium in the cold storage medium container. Thereafter, when the compressor stops due to engine idling stop or other reasons, the air is cooled by using cooling capacity stored by the cold storage medium so that cooling performance is preserved.